Le 02/04/2021 à 12:53, arctica1963 a écrit :
Hi Stephane,

At the moment I am just trying to understand how Scilab works with triple
integration of f(x,y,z) with limits for xyz.

Ok, when you say "limits" for xyz you mean that each variable varies in a given constant interval, that's what I meant by the rectangular parallelepiped [x1,x2] x [y1,y2] x [z1,z2]. In fact it is a pity that Scilab does not handle this case but only the more general case of a collection of (eventually disconnected) tetrahedrons. However, cutting your parallepiped in 5 (https://www.geogebra.org/m/C3TjXxFY)  is enough to use int3d, since they will be recursively divided to attain the required precision:

deff('v=f(xyz,numfun)','v=xyz(1)^2+xyz(2)^2+xyz(3)^2')
xlim=[0  1];
ylim=[0  1];
zlim=[0  1];
[x,y,z]=ndgrid(xlim,ylim,zlim);
i  =  [5  8  2  3
     5  8  2  6
     5  8  3  7
     5  2  3  1
     2  3  8  4]';
[result,err] = int3d(x(i),y(i),z(i),f) --> result result = 1.0000000 --> err err = 1.110D-14

S.

Lester



--
Sent from: 
https://antispam.utc.fr/proxy/1/c3RlcGhhbmUubW90dGVsZXRAdXRjLmZy/mailinglists.scilab.org/Scilab-users-Mailing-Lists-Archives-f2602246.html
_______________________________________________
users mailing list
users@lists.scilab.org
https://antispam.utc.fr/proxy/1/c3RlcGhhbmUubW90dGVsZXRAdXRjLmZy/lists.scilab.org/mailman/listinfo/users

--
Stéphane Mottelet
Ingénieur de recherche
EA 4297 Transformations Intégrées de la Matière Renouvelable
Département Génie des Procédés Industriels
Sorbonne Universités - Université de Technologie de Compiègne
CS 60319, 60203 Compiègne cedex
Tel : +33(0)344234688
http://www.utc.fr/~mottelet

_______________________________________________
users mailing list
users@lists.scilab.org
http://lists.scilab.org/mailman/listinfo/users

Reply via email to